In vitro activities of a novel nanoemulsion against Burkholderia and other multidrug-resistant cystic fibrosis-associated bacterial species.
Respiratory tract infection, most often involving opportunistic bacterial species with broad-spectrum antibiotic resistance, is the primary cause of death in persons with cystic fibrosis (CF). Species within the Burkholderia cepacia complex are especially problematic in this patient population. We investigated a novel surfactant-stabilized oil-in-water nanoemulsion (NB-401) for activity against 150 bacterial isolates recovered primarily from CF respiratory tract specimens. These specimens included 75 Burkholderia isolates and 75 isolates belonging to other CF-relevant species including Pseudomonas, Achromobacter, Pandoraea, Ralstonia, Stenotrophomonas, and Acinetobacter. Nearly one-third of the isolates were multidrug resistant, and 20 (13%) were panresistant based on standard antibiotic testing. All isolates belonging to the same species were genotyped to ensure that each isolate was a distinct strain. The MIC(90) of NB-401 was 125 microg/ml. We found no decrease in activity against multidrug-resistant or panresistant strains. MBC testing showed no evidence of tolerance to NB-401. We investigated the activity of NB-401 against a subset of strains grown as a biofilm and against planktonic strains in the presence of CF sputum. Although the activity of NB-401 was decreased under both conditions, the nanoemulsion remained bactericidal for all strains tested. These results support NB-401's potential role as a novel antimicrobial agent for the treatment of infection due to CF-related opportunistic pathogens.
LiPuma
John J
JJ
Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan 48109, USA. jlipuma@umich.edu
Rathinavelu
Sivaprakash
S
Foster
Bridget K
BK
Keoleian
Jordan C
JC
Makidon
Paul E
PE
Kalikin
Linda M
LM
Baker
James R
JR
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects; D019117:Burkholderia / Q000187:drug effects* / Q000302:isolation & purification; D003550:Cystic Fibrosis / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D004655:Emulsions / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D053758:Nanoparticles; D013183:Sputum / Q000382:microbiology
D000900:Anti-Bacterial Agents; D004655:Emulsions